1. echo or reflect sound, light or heat.   Hint First letter clue   2. pass through pores; happen.   First letter clue   3. collide with or dash against.   First letter clue   4. exhaust vigor of or undermine.   First letter clue   5. introduce into a larger body or unite.   First letter clue   6. mean or insinuate.   First letter clue   7. handle or control craftily.   First letter clue